The alpha-tocopherol-induced phenotypes of the rotifer Asplanchna sieboldi will be compared to the phenotype expressed in the absence of dietary alpha-tocopherol. Especial emphasis will be placed on the determination of DNA per nucleus using microspectrocytophotometry and of differences in enzyme levels and activities. Levels of tocopherol and a new, unknown compound with tocopherol activity will be analyzed in natural freshwater ecosystems using spectrofluorometry and rotifer bioassay. BIBLIOGRAPHIC REFERENCES: Litton, J.R., Jr. and J.J. Gilbert. 1975. Analysis of tocopherol in Rhodotorula glutinis, Agaricus campestris and Euglena gracilis using spectrofluorometry and rotifer bioassay. J. Gen. Appl. Microbiol. 21:345-354. Gilbert, J.J. 1976. Polymorphism in the rotifer Asplanchna sieboldi: biomass, growth and reproductive rate of the saccate and campanulate morphotypes. Ecology. in press.